A Low-Power Sub-GHz RF Receiver Front-End With Enhanced Blocker Tolerance

Sub-GHz wireless systems have become a popular choice for Internet-of-Things (IoT) applications due to their lower cost, lower power consumption and longer transmission range compared to their 2.4 GHz counterpart. This thesis presents a class-AB sub-GHz RF receiver front-end for low power IoT applications. By exploiting transistors' class-AB operation in both the RF and baseband sections, the receiver front-end achieves a very low sensitivity and an elevated blocker tolerance while keeping a low power consumption. Such performance makes the receiver fully compliant with the short-range (e.g. IEEE 802.15.4) application and also suitable for the emerging long-range (e.g. LoRa) application. The proposed RF receiver front-end has been implemented in 0.13um CMOS technology, operates in the 868/915MHz ISM bands, and exhibits an in-band gain of 50dB, noise figure of 2.7dB, out-of-band IIP3 of +2dBm, out-of-band IIP2 of +37dBm, out-of-band P1dB of -10.5dBm, while draining 2.1mA from a 1.2V supply.M.A.S

Improvement of Accuracy in Damage Localization Using Frequency Slice Wavelet Transform

Damage localization is a primary objective of damage identification. This paper presents damage localization in beam structure using impact-induced Lamb wave and Frequency Slice Wavelet Transform (FSWT). FSWT is a new time-frequency analysis method and has the adaptive resolution feature. The time-frequency resolution is a vital factor affecting the accuracy of damage localization. In FSWT there is a unique parameter controlling the time-frequency resolution. To improve the accuracy of damage localization, a generalized criterion is proposed to determine the parameter value for achieving a suitable time-frequency resolution. For damage localization, the group velocity dispersion curve (GVDC) of A0 Lamb waves in beam is first accurately estimated using FSWT, and then the arrival times of reflection wave from the crack for some individual frequency components are determined. An average operation on the calculated propagation distance is then performed to further improve the accuracy of damage localization

Frequency slice algorithm for modal signal separation and damping identification

The present study examined in case of papillary renal cell carcinoma (pRCC) whether there consists a correlation between kind and number of the cytogenetic changes and clinical progress, in order to win conclusions of the prognostic relevance of the cytogenetic. Material and methods: Between 1988 and 1997 altogether 31 pRCC of 30 patients were cytogenetically analyzed by short time cultures. The histomorphologic grading oriented itself at the classification of Thoenes et al. (1991) and at the WHO classification for epithelial RCC (Mostofi 1997). In 24 cases the samples have been preparated by radical nephrectomies, in 6 cases by partial resection and in one case the tissue originated from a lymph node. The follow-up data ended in 2001. Results: The cytogenetic dressing showed that both primary and secondary aberrations were clearly presented.. The chromosomes 4 and 10 were involved in no case of the 31 pRCC. There has been no remarkable association of the tumor size and aberration of certain chromosomes. Some authors describe a correlation between trisomy 16 and a higher malignant tendency of the tumor. This could not be verified in this study. With two exceptions all patients with well differentiated pRCC showed complete remission independent from the tumor size. In one case a local lesion after enukleation was observed. Seven of the 30 patients died, 2 of them reliably because of the pRCC. Nine of the 30 patients developed a malignant second desease. Discussion: The aberrations followed a chronological sequence, but did not present a correlation between tumor-size, quantity or quality of the aberrations and the clinical progress. The difficulty to evaluate the progress consisted of the fact that the patients immediately after diagnosis have been treated by surgery. This examination did not demonstrate that the cytogenetic obtains prognostic relevance